Ginseng (American)

Health Care Professional Information

Scientific Name
Panax quinquefolius
Common Name

Xi yang shen, Tienchi ginseng, western ginseng, five-fingers

Clinical Summary

American ginseng is cultivated in the northwest regions of United States and Canada. Patients take this supplement to improve athletic performance, strength, and stamina, and to treat diabetes and cancer. In Chinese herbal formulas, American ginseng is frequently used to nourish “Yin” (1). The saponin glycosides, also known as ginsenosides or panaxosides, are thought responsible for American ginseng's effects.
Ginsenosides have both stimulatory and inhibitory effects on the CNS (4), alter cardiovascular tone, enhance humoral and cellular-dependent immunity, and have anticancer effects in vitro (3) (15) (16).

Current data suggest that ginseng may improve glucose control in diabetics (2) (6), but additional research is necessary. It demonstrated a modest effect in reducing the number and severity of colds (12); and enhanced working memory in healthy adults (21) and in patients with schizophrenia (24).

The anticancer effects of ginseng were enhanced when combined with antioxidants (14). Ginseng also acts synergistically with 5-fluorouracil against colorectal cancer cells (17) and demonstrated radioprotective effects in irradiated human lymphocytes (18).
Data from an epidemiological study show that ginseng improves survival and quality of life in breast cancer patients (13). Findings from a randomized controlled trial support its benefits in improving cancer-related fatigue (23).

Purported Uses
  • Cancer prevention
  • Cancer treatment
  • Diabetes
  • Health maintenance
  • Immunostimulation
  • Strength and stamina
Constituents
  • Saponin glycosides: Panaquilon, ginsenosides
  • Volatile oils
  • Antioxidants
  • Polysaccharides
  • Fatty acids
  • Vitamins
  • Polyacetylenes
    (5)
Mechanism of Action

Ginsenosides are thought responsible for American ginseng's activity, although the exact mechanism of action is unknown. American ginseng lowers serum glucose and may affect carbohydrate metabolism (2) (6). Related species, such as Panax ginseng, have been the focus of most laboratory and clinical research. Experiments using extracts from these species indicate that ginsenosides stimulate and inhibit the CNS (4). The extracts also stimulate TNF alpha production by alveolar macrophages (10). The Rg1 ginsenoside is associated with improvements in humoral and cell-mediated immune response and increases in T helper cells, T lymphocytes, and NK cells in mice (5). Ginseng's antagonistic effect on warfarin is not due to vitamin K (11)

Several ginsenosides demonstrated anticancer properties in vitro (3). However, current data suggest that the antiproliferative effects of American ginseng are due to compound K, a metabolite of the ginsenoside Rb1, but not Rb1 as previously thought (22).

Pharmacokinetics

In a rabbit model, the pharmacokinetics of ginsenosides A1, A2, B2, and C were best described with a one-component open model. Ginsenoside C (protopanaxadiol group ginseng saponin) showed a significantly longer half-life, higher plasma protein binding, and lower metabolic and renal clearance compared to A1, A2, and B2 (protopanaxatriol group ginseng saponins).
All ginsenosides except ginsenoside A1 were absorbed slowly after intraperitoneal administration. Ginsenosides were not found in rabbit plasma or urine samples after oral administration.
In mice, ginsenoside C was more toxic than ginsenoside A2 following intraperitoneal administration.
None of the ginsenosides caused toxicity following oral administration. (5)

Contraindications

Breast cancer patients should use this product with caution as ginseng may stimulate the growth of breast cancer cells (9).

Herb-Drug Interactions

Warfarin: Ginseng has been shown to antagonize warfarin's effects (11).
Cytochrome P450 (CYP) 3A4 substrates: Certain ginsenosides can induce CYP3A4 and may affect the metabolism of some drugs that are substrates of this enzyme (19) (20).

Herb Lab Interactions

Reductions in PT, PTT, and INR and blood glucose may occur.
(8) (11)

Literature Summary and Critique

Barton DL, Liu H, Dakhil SR, et al. Wisconsin Ginseng (Panax quinquefolius) to improve cancer-related fatigue: a randomized, double-blind trial, N07C2. J Natl Cancer Inst. 2013 Aug 21;105(16):1230-8.
In this phase III trial, 364 fatigued cancer survivors were randomized to 2000mg of American ginseng or a placebo for 8 weeks. The primary endpoint was the general subscale of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) at 4 weeks. Deviations from the baseline were measured at 4 and 8 weeks by a two-sided, two-sample t test. Toxicities were determined by self-report and the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE) provider grading.
Researchers reported that changes in the MFSI-SF were 14.4 (standard deviation [SD] = 27.1) in the ginseng group vs 8.2 (SD = 24.8) in the placebo group at 4 weeks (P = .07). At 8 weeks, a statistically significant difference was observed with a change score of 20 (SD = 27) for the ginseng group and 10.3 (SD = 26.1) for the placebo group (P = .003). Patients undergoing active cancer treatment benefited more compared to those who had completed treatment. There were no adverse effects following ginseng supplementation.
American ginseng improved cancer-related fatigue taken over an 8-week period.

Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin's effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.
Twenty healthy adults took part in a four-week trial of ginseng and its effects on warfarin. All subjects received warfarin during weeks 1 and 4. Subjects were randomly assigned to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects receiving ginseng had significantly decreased International Normalized Ratios (INR) when compared with those receiving placebo. Peak INR and peak plasma warfarin levels were correlated. Researchers concluded that ginseng reduces warfarin's anticoagulant effect.

Dosage (Inside MSKCC Only)
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References
  1. Huang KC. The Pharmacology of Chinese Herbs, 2nd ed. New York: CRC Press; 1999.
  2. Vuksan V, et al. American ginseng (Panax quinquefolius L) reduces postprandial glycemia in nondiabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med 2000;160:1009-13.
  3. Shin HR, et al. The cancer-preventive potential of Panax ginseng: a review of human and experimental evidence. Cancer Causes Control 2000;11:565-76.
  4. Attele AS, Wu JA, Yuan CS. Ginseng pharmacology: multiple constituents and multiple actions. Biochem Pharmacol 1999;58:1685-93.
  5. Chen SE. American ginseng. III. Pharmacokinetics of ginsenosides in the rabbit. Eur J Drug Metab Pharmacokinet 1980;5:161-8.
  6. Vuksan V, et al. American ginseng (Panax quinquefolius L.) attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals. Am J Clin Nutr 2001;73:753-8.
  7. Brinker F. Herb Contraindications and Drug Interactions, 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.
  8. Vuksan V, et al. American ginseng improves glycemia in individuals with normal glucose tolerance: effect of dose and time escalation. J Am Coll Nutr 2000;6:738-44.
  9. Amato P, Christophe S, Mellon PL. Estrogenic activity of herbs commonly used as remedies for menopausal symptoms. Menopause 2002;9:145-50.
  10. Assinewe VA, et al. Extractable polysaccharides of Panax quinquefolius L. (North American ginseng) root stmulate TNFalpha production by alveolar macrophages. Phytomedicine 2002;9:398-404.
  11. Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin's effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.
  12. Predy GN, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infectons: a randomized controlled trial. CMAJ 2005;173(9):1043-8.
  13. Cui Yong, et al. Association of ginseng use with survival and quality of life among breast cancer patients. Am J Epidemiol 2006; 163(7):645-53.
  14. Li B, Wang CZ, He TC, et al. Antioxidants potentiate American ginseng-induced killing of colorectal cancer cells. Cancer Letters. 2010;289(1):62-70.
  15. Li B, Zhao J, Wang CZ, et al. Ginsenoside Rh2 induces apoptosis and paraptosis-like cell death in colorectal cancer cells through activation of p53. Cancer Lett. 2011 Feb 28;301(2):185-92.
  16. Xie JT, Du GJ, McEntee E, et al. Effects of Triterpenoid Glycosides from Fresh Ginseng Berry on SW480 Human Colorectal Cancer Cell Line. Cancer Res Treat. 2011 Mar;43(1):49-55.
  17. Li XL, Wang CZ, Sun S, et al. American ginseng berry enhances chemopreventive effect of 5-FU on human colorectal cancer cells. Oncol Rep. 2009 Oct;22(4):943-52.
  18. Lee TK, O'Brien KF, Wang W, et al. Radioprotective effect of American ginseng on human lymphocytes at 90 minutes postirradiation: a study of 40 cases. J Altern Complement Med. 2010 May;16(5):561-7.
  19. Hao M, Ba Q, Yin J, et al. Deglycosylated ginsenosides are more potent inducers of CYP1A1, CYP1A2 and CYP3A4 expression in HepG2 cells than glycosylated ginsenosides. Drug Metab Pharmacokinet. 2011;26(2):201-5.
  20. Hao M, Zhao Y, Chen P, et al. Structure-activity relationship and substrate-dependent phenomena in effects of ginsenosides on activities of drug-metabolizing P450 enzymes. PLoS One. 2008 Jul 16;3(7):e2697.
  21. Scholey A, Ossoukhova A, Owen L, et al. Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study. Psychopharmacology (Berl). 2010 Oct;212(3):345-56.
  22. Wang CZ, Du GJ, Zhang Z, et al. Ginsenoside compound K, not Rb1, possesses potential chemopreventive activities in human colorectal cancer. Int J Oncol. 2012 Jun;40(6):1970-6.
  23. Barton DL, Liu H, Dakhil SR, et al. Wisconsin Ginseng (Panax quinquefolius) to improve cancer-related fatigue: a randomized, double-blind trial, N07C2. J Natl Cancer Inst. 2013 Aug 21;105(16):1230-8.
  24. Chen EY, Hui CL. HT1001, a proprietary North American ginseng extract, improves working memory in schizophrenia: a double-blind, placebo-controlled study. Phytother Res. 2012 Aug;26(8):1166-72.

Consumer Information

How It Works

Bottom Line: American ginseng has not been shown to treat or prevent cancer.

American ginseng has been shown to lower blood sugar levels in humans. Scientists think that the effects of ginseng come from its components called ginsenosides. Most research has been done on another species, Panax ginseng. These studies indicate that ginsenosides both stimulate and inhibit the central nervous system in humans and stimulate the immune system in mice. Laboratory studies in mice and population studies in humans suggest that Panax ginseng has cancer-preventative properties.
American ginseng was shown to reduce the number and severity of colds, and improve working memory in healthy adults.
It also decreases the anticoagulant effects of warfarin, an anticoagulant.

Purported Uses
  • To improve athletic performance
    No scientific evidence supports this use.
  • To prevent and treat cancer
    There are no data to back this claim. But ginseng helps improve cance-related fatigue and improves quality of life.
  • To treat diabetes
    A few studies show a blood glucose-lowering effect of American ginseng.
  • To stimulate the immune system
    Some studies show an immunostimulant effect in animals. Human data are lacking.
  • For increased strength and stamina
    Although ginseng is often promoted for this use, human data are lacking.
Research Evidence

Cancer-related fatigue:
In this study, 364 fatigued cancer survivors were randomized to receive 2000mg of American ginseng or a placebo for 8 weeks. Those who took ginseng had significant improvement in their fatigue. Patients who were undergoing active treatment benefited more than those who completed treatment. No serious side effects were reported.
These results suggest that American ginseng helps improve fatigue in cancer patients.

Interaction with Warfarin:
Twenty healthy adults received warfarin during weeks 1 and 4 in this study. They were then randomized to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects who received ginseng had signficantly lowered International Normalized Ratios (INR) when compared with those receiving placebo. Researchers conclude that ginseng reduces warfarin's anticoagulant effect and suggest that physicians ask their patients about ginseng use before prescribing warfarin.

Do Not Take If
  • You are taking warfarin or other blood thinners (American ginseng may interfere with the action of the anticoagulant).
  • You are taking drugs that are substrates of cytochrome P450 (CYP) 3A4 (American ginseng may make the drugs less effective).
Special Point

Breast cancer patients should use this product with caution as ginseng may stimulate the growth of breast cancer cells.

E-mail your questions and comments to aboutherbs@mskcc.org.